I think these sticky fly strips have been around for at least a hundred years. I can remember my Grandpa hanging them up in his workshop and in the big barn so I know they've been around for forty years at least. I remember having a mild fascination with them. They're called "fly catchers", but they catch anything that gets stuck to them. Anything that doesn't have the weight or the strength to pull itself free. Moths, junebugs, wasps, horseflies, mosquitos, bees, etc... The fly strips catch and kill flying insects indiscriminately. Good bugs. Bad bugs. It makes no distinction. Most of the time I don't either. Bugs are bugs.

I bought two packages online last year for $1.29 each. With tax and shipping the total came to $10.24, meaning I paid $1.28 for each individual fly strip, a penny less than the price of a four-pack. That "per unit" average cost would go down considerably the more I bought.

I used to think there was some sort of insect attractant added to the glue of the fly strips. Pheromones or something like them that lured bugs in to their sticky deaths. It would explain why so many bugs get caught on them. I think that might have to have FDA approval (just guessing here) so it's probably not the case. A more likely reason why so many bugs get caught on them is that they're attracted by the sounds of the other bugs that have already been stuck to the glue. That would explain it also.

No pheromones. Not unless they've covertly slipped them in with the inert ingredients.

There's a certain kind of fly that hangs around my garage. I have a small workshop in my garage and I'm out there quite a bit when the weather is nice. This isn't an ordinary housefly. I don't know what kind of fly it is but it's extremely annoying. Slightly smaller than a housefly, these flies congregate in small swarms around the immediate vicinity of a 12-inch pull cord hanging down from the open garage door. They always swarm in the same place. They're fascinated by that dangling rope and forty or fifty of them will be massed around it at any given time. Never in small numbers. You won't ever see just four or five of them flying around. It's always these thick little swarms of maybe fifty or so. Their flying ability sucks too. I've had them crash land in my mouth, my eyes, my hair. They're extremely annoying and I haven't made any attempt to co-exist with them whatsoever. A fly strip hung right beside the pull cord catches literally hundreds of them within days of my putting it there. They're attracted to it just as they are the cord and the fly catcher is an effective way of controlling them.

The bad thing about these bug traps is that don't store well. Either that or they sent me a defective product. I used four of them last year and had four remaining this spring when the flies returned. Of those four, three had dried completely out and couldn't be used. Not only had the sticky adhesive dried out, the paper strip had turned brittle and kept breaking every time I tried to pull it out. The fourth trap had dried out only partially and could still be used. Limited shelf live or, again, maybe they sent me a defective package.